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Rapid Determination of Compositions of Blended Oils by Matrix-assisted Laser Desorption/Ionization Mass Spectrometry and Partial Least Squares Regression

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Rapid Determination of Compositions of Blended Oils by Matri...

‘Whole-molecule Disorder’ Refinement of 4-Tricyanovinyl-N,N-diethylaniline

2018年中国质谱学术大会（CMSC2018）

作者： Suying Li tsz-Tsun ng Zhong-Ping Yao Department of Applied Biology and Chemical Technology The Hong Kong Polytechnic University

Different edible oil species have different triacylglycerols(TAGs) patterns which can be used as fingerprints for authentication of edible oils. Matrix-assisted laser desorption/ionization mass spectrometry(MALDIMS) has been demonstrated to be an effective tool for profiling TAGs in edible oils,1 and it is feasible to classify edible oils based on the MALDI-MS profiling and statistical analysis.2 Mislabeling of oil compositions for better profits is a problem encountered in the market of blended oils. At the same time, authentic method for quantitation of blended oils is still lacking due to the varied blending modes and complex TAGs profiles. Therefore, we applied partial least squares regression(PLS-R), a multivariate regression method, to analyze the MALDI-MS spectra of blended oils and established a quantitative method for simultaneous determination of all compositions of blended oils. This method produced quantitative results that were comparable to those using conventional gas chromatography flame ionization detector(GC-FID) method, but was simpler and more effective as it required no sample pretreatment and chromatographic separation. Different types of blended oils, including binary blended oils, ternary blended oils and quaternary blended oils, have been successfully analyzed by the method, and the compositions of several commercial blended oil products were also quantified in this study.

关键词： Quantitation blended oil,MALDI-MS,PLS-R

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Chinese Journal of Structural Chemistry 2011年第9期30卷 1286-1288页

作者： ng Seik Weng Department of Chemistry University of Malaya Chemistry Department Faculty of Science King Abdulaziz University

The molecule of 4-tricyanovinyl-N,N-diethylaniline is disordered about an axis that is close to the axis passing through the 1,4-carbon atoms. The disorder is a 1：1 type of disorder that involves only part of the molecule as the diethylamino substitutent and the three nitrogen atoms of the tricyanovinyl substituent are ordered. The treatment of the nearly ‘whole-molecule disorder’ by employing a small number of restraints is described. Crystal data： C15H14N4, triclinic, P , a = 7.1996（5）, b = 7.7232（5）, c = 12.4171（8） , α = 99.350（1）, β = 94.647（1）, γ = 103.312（1）o and V = 657.90（8） 3 at –173 K.

关键词： whole-molecule disorder

Cancers of the lung, head and neck on the rise: perspectives on the genotoxicity of air pollution

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Chinese Journal of Cancer 2014年第10期33卷 476-480页

作者： Ian Chi Kei Wong Yuen-Keng ng Vivian wai Yan Lui Pharmacogenomics and Precision Therapeutics Laboratory Department of Pharmacology and PharmacyLi Ka Shing Faculty of MedicineThe University of Hong Kong

Outdoor air pollution has been recently classified as a class I human carcinogen by the World Health Organization(WHO). Cumulative evidence from across the globe shows that polluted air is associated with increased risk of lung, head and neck, and nasopharyngeal cancers—all of which affect the upper aerodigestive tract. Importantly, these cancers have been previously linked to smoking. In this article, we review epidemiologic and experimental evidence of the genotoxic and mutagenic effects of air pollution on DNA, purportedly a key mechanism for cancer development. The alarming increase in cancers of the upper aerodigestive tract in Asia suggests a need to focus government efforts and research on reducing air pollution, promoting clean energy, and investigating the carcinogenic effects of air pollution on humans.

关键词：空气污染头颈部癌症遗传毒性肺癌世界卫生组织上升实验证据

Prostate cancer detection upon transrectal ultrasound-guided biopsy in relation to digital rectal examination and prostate-specific antigen level： what to expect in the Chinese population？

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Asian Journal of Andrology 2015年第5期17卷 821-825,I0010页

作者： Jeremy YC Teoh Steffi KK Yuen James HL Tsu Charles KW Wong Brian SH Ho Ada TL ng wai-Kit Ma Kwan-Lun Ho Ming-Kwong Yiu Department of Surgery Division of Urology Queen Mary Hospital University of Hong Kong Hong Kong China

We investigated the prostate cancer detection rates upon transrectal ultrasound （TRUS）-guided biopsy in relation to digital rectal examination （DRE） and prostate-specific antigen （PSA）, and risk factors of prostate cancer detection in the Chinese population. Data from all consecutive Chinese men who underwent first TRUS-guided prostate biopsy from year 2000 to 2013 was retrieved from our database. The prostate cancer detection rates with reference to DRE finding and PSA level of 〈 4, 4-10, 10.1-20, 20.1-50 and 〉 50 ng ml^-1 were investigated. Multivariate logistic regression analyses were performed to investigate for potential risk factors of prostate cancer detection. A total of 2606 Chinese men were included. In patients with normal DRE, the cancer detection rates were 8.6%, 13.4%, 21.8%, 41.7% and 85.2% in patients with PSA 〈 4, 4-10, 10.1-20, 20.1-50 and 〉 50 ng ml^-1 respectively. In patients with abnormal DRE, the cancer detection rates were 12.4%, 30.2%, 52.7%, 80.6% and 96.4% in patients with PSA 〈 4, 4-10, 10.1-20, 20.1-50 and 〉 50 ng m1-1 respectively. Older age, smaller prostate volume, larger number of biopsy cores, presence of abnormal DRE finding and higher PSA level were associated with increased risk of prostate cancer detection upon multivariate logistic regression analyses （P 〈 0.001）. Chinese men appeared to have lower prostate cancer detection rates when compared to the Western population. Taking the different risk factors into account, an individualized approach to the decision of TRUS-guided biopsy can be adopted.

关键词： Chinese digital rectal examination prostate biopsy prostate cancer prostate-specific antigen

The roles of black phosphorus in performance enhancement of halide perovskite solar cells

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Journal of Energy Chemistry 2022年第4期31卷 672-683页

作者： Damir Aidarkhanov Charles Surya Annie ng Department of Electrical and Computer Engineering School of Engineering and Digital SciencesNazarbayev UniversityKabanbay Batyr Ave.53Nur-Sultan 010000Kazakhstan Innovation and Technology Commission Central Government Offices2 Tin Mei AvenueHong Kong 999077China

Hybrid organic-inorganic perovskite solar cells(PSCs) are considered to be the most promising thirdgeneration photovoltaic(PV) technology with the most rapid rate of increase in the power conversion efficiency(PCE). To date, their PCE values are comparable to the established photovoltaic technologies such as crystalline silicon. Intensive research activities associated with PSCs have been being performed,since 2009, aiming to further boost the device performance in terms of efficiency and stability via different strategies in order to accelerate the progress of commercialization. The emerging 2 D black phosphorus(BP) is a novel class of semiconducting material owing to its unique characteristics, allowing them to become attractive materials for applications in a variety of optical and electronic devices, which have been comprehensively reviewed in the literature. However, comprehensive reviews focusing on the application of BP in PSCs are scarce in the community. This review discusses the research works with the incorporation of BP as a functional material in PSCs. The methodology as well as the effects of employing BP in different regions of PSCs are summarized. Further challenges and potential research directions are also highlighted.

关键词： Perovskite solar cells Black phosphorus Power conversion efficiency Stability Low dimensional materials

FOTool: Modelling Indigenous Community Cultures in Sarawak

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Journal of Software Engineering and Applications 2014年第8期7卷 720-729页

作者： Edwin Mit ng Bong Ding Cheah wai Shiang Faculty of Computer Science and Information Technology Universiti Malaysia Sarawak Kota Samarahan Malaysia

Formal-Object Tool (FOTool) is a software modelling approach that integrates formal specification and object oriented model. FOTool integrates the rigour of formal methods and the ease of use of OO techniques. The idea of FOTool is to provide an easy interface by allowing the application developer to develop the software model by using the object-models, while the verification of the models is carried out by using formal models. Before the verification process, the object static and dynamic models need to be transformed into formal models based on the transformation rules defined in FOTool. This paper presents the FOTool architecture, the transformation rules from object to formal models, and discusses the application of FOTool in our continuous research in modeling, the indigenous communities’ knowledge in Sarawak, and also the challenges of modelling the complex cultural, taboos and beliefs of indigenous communities. The knowledge is generated from the heterogeneous cultural, taboos and beliefs of various ethnic groups in Sarawak. The traditional knowledge is then mapped to a logical explanation in relation to modern life style.

关键词： Software Modelling Formal Method Object Model Model Integration

NUMERICAL STUDIES OF A CLASS OF COMPOSITE PRECONDITIONERS

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Journal of Computational Mathematics 2014年第2期32卷 136-151页

作者： Qiang Niu Michael ng Mathematics and Physics Centre Xi'an Jiaotong-Liverpool University Suzhou 215123 China Department of Mathematics Hong Kong Baptist University Kowloon Tong Hong Kong

In this paper, we study a composite preconditioner that combines the modified tangential frequency filtering decomposition with the ILU（O） factorization. Spectral property of the composite preconditioner is examined by the approach of Fourier analysis. We illustrate that condition number of the preconditioned matrix by the composite preconditioner is asymptotically bounded by O（hp -2/3） on a standard model problem. Performance of the composite preconditioner is compared with other preconditioners on several problems arising from the discretization of PDEs with discontinuous coefficients. Numerical results show that performance of the proposed composite preconditioner is superior to other relative preconditioners.

关键词： Preconditioner ILU Tangential frequency filtering decomposition GMRES.

Lowered testosterone in male obesity： mechanisms, morbidity and management

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Asian Journal of Andrology 2014年第2期16卷 223-231,I0008页

作者： Mark ng Tang Fui Department of Medicine Austin Health University of Melbourne Melbourne Department of Endocrinology Austin Health Melbourne Victoria Australia

With increasing modernization and urbanization of Asia, much of the future focus of the obesity epidemic will be in the Asian region. Low testosterone levels are frequently encountered in obese men who do not otherwise have a recognizable hypothalamic-pituitary-testicular （HPT） axis pathology. Moderate obesity predominantly decreases total testosterone due to insulin resistance-associated reductions in sex hormone binding globulin. More severe obesity is additionally associated with reductions in free testosterone levels due to suppression of the HPT axis. Low testosterone by itself leads to increasing adiposity, creating a self-perpetuating cycle of metabolic complications. Obesity-associated hypotestosteronemia is a functional, non-permanent state, which can be reversible, but this requires substantial weight loss. While testosterone treatment can lead to moderate reductions in fat mass, obesity by itself, in the absence of symptomatic androgen deficiency, is not an established indication for testosterone therapy. Testosterone therapy may lead to a worsening of untreated sleep apnea and compromise fertility. Whether testosterone therapy augments diet- and exercise-induced weight loss requires evaluation in adequately designed randomized controlled clinical trials.

关键词： androgens hypogonadism obesity testosterone weight loss

On compact splitting complex submanifolds of quotients of bounded symmetric domains

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Science China Mathematics 2017年第6期60卷 1057-1076页

作者： MOK ngaiming ng SuiChung Department of Mathematics The University of Hong Kong Department of Mathematics Shanghai Key Laboratory of PMMPEast China Normal University

We study compact complex submanifolds S of quotient manifolds X =Ω/F of irreducible bounded symmetric domains by torsion free discrete lattices of automorphisms, and we are interested in the characterization of the totally geodesic submanifolds among compact splitting complex submanifolds S C X, i.e., under the assumption that the tangent sequence over S splits holomorphically. We prove results of two types. The first type of results concerns S C X which are characteristic complex submanifolds, i.e., embedding Ω as an open subset of its compact dual manifold M by means of the Borel embedding, the non-zero （1, 0）-vectors tangent to S lift under a local inverse of the universal covering map π → X to minimal rational tangents of M. We prove that a compact characteristic complex submanifold S C X is necessarily totally geodesic whenever S is a splitting complex submanifold. Our proof generalizes the case of the characterization of totally geodesic complex submanifolds of quotients of the complex unit ball B^n obtained by Mok （2005）. The proof given here is however new and it is based on a monotonic property of curvatures of Hermitian holomorphic vector subbundles of Hermitian holomorphic vector bundles and on exploiting the splitting of the tangent sequence to identify the holomorphic tangent bundle Ts as a quotient bundle rather than as a subbundle of the restriction of the holomorphic tangent bundle Tx to S. The second type of results concerns characterization of total geodesic submanifolds among compact splitting complex submanifolds S C X deduced from the results of Aubin （1978） and Yau （1978） which imply the existence of Kahler-Einstein metrics on S C X. We prove that compact s- plitting complex submanifolds S C X of sufticiently large dimension （depending on ） are necessarily totally geodesic. The proof relies on the Hermitian-Einstein property of holomorphic vector bundles associated to TS, which implies that endomorphisms of such bundles are parallel, and the co

关键词： bounded symmetric domains tangent sequence splitting complex submanifolds varieties of minimal rational tangents K/ihler-Einstein metrics